IAM folder-level permissions cause tablesnap to fail

[tightly-clutched]

I've set up folder-level permission in AWS IAM following this guide. So my dev user has all permissions on s3://tablesnap/backups/dev/, for example.

invoking tablesnap with --prefix backups/dev/ fails silently. the only entry in syslog is tablesnap: Starting up and no files are transferred. I can read, write, delete to the folder using the awscli, so I know the permissions are correct.

[tightly-clutched]

looks like this is due to the way the prefix is used in tablesnap. It seems to me that prefix is used to construct the filename, whereas the folder-level permissions are expecting /s3-bucket/prefix/ and then the bare filename.